In computer systems, particularly small or personal computer systems, peripheral devices make up a large part of the cost of the system. Where possible, it is desirable to share peripheral devices between several computer systems.
In small computer systems, especially personal computer systems, the hardware and operating system software may lack the sophistication necessary to allow such sharing. Therefore, if peripherals in such systems are to be shared, the user of the system must manually re-initialize the peripheral device each time the computer systems are switched. This is very time consuming, and very difficult if the computer systems that share the device are not in close proximity.
For some peripheral devices, such as printers, prior art manual switches may be used to switch the electrical connections from one computer system to another. Each time the interface to the peripheral is switched, the computer now having control of the peripheral must re-initialize the peripheral to reestablish the state of the peripheral device. In the case of printers, this reinitialization involves restoring the printing resolution, page orientation (landscape or portrait), margins, fonts selected, page size, and many other parameters. If the printer is being used by a word processing system, the user may not be aware of these parameters, and thus may be unable to re-initialize the printer to the state it had before being switched to the other computer system.
There is a need in the art then for a peripheral switch that allows a peripheral device to be shared between two or more computer systems. There is further need in the art for such a switch that saves the state of the peripheral device for each of the sharing computer systems. A still further need is for such a switch that automatically restores the state of the peripheral each time the interface is switched, thus providing transparent switching. The present invention meets these needs.